This single seal breakaway connector relates in general to means for allowing fuel to flow through a line but abruptly stopping fuel passage through the line upon application of sufficient axial force. Such axial force often arises when an errant motorist drives away from a fuel pump. The connector sees use in a flow line, such as a gasoline line connecting to a nozzle used by motorists for fuel dispensing at a service station. The connector more specifically relates to improvements within it useful for installing upon coaxial hoses, fittings, and nozzles and later when a severance occurs along the line and when a loss of fuel may be encountered, such as when a vehicle drives off with the nozzle inadvertently still inserted within the vehicle fuel tank. Unique aspects of the present connector are a smooth exterior between its two halves, faces suitable for gripping by a wrench or other tool, and a flow constriction interior of the check valves. This invention is especially useful when applied in a fuel line at its connection to a pump, at a splice of two lines, or proximate a nozzle and it functions as a check valve to prevent fuel flow under emergency adverse conditions, particularly when the breakaway hose is disconnected.
Numerous connectors and valves in the prior art furnish a shut-off of fluid or other fuel flow, and more particularly, such mechanisms normally are utilized in lines where fuel may be flowing, and generally in those situations when the conduit comprises the fuel line leading from a fuel dispenser to its nozzle. For example, as can be seen in the U.S. Pat. No. 2,642,297, to Hanna, a breakaway coupling responds to tension in the line and is held together through a combination of male and female couplings, and detents that provide bearing engagement between the two components. In addition, the U.S. Pat. Nos. 4,617,975, and 4,691,941, to Rabushka, discloses various types of tension actuated uncouplers, for delivering gasoline to a vehicle from a gas pump. These prior patents portray devices that tend to leak, and when any internal pressure is exerted within the fuel line, such as may occur when pumping the fuel, excessive pressures may momentarily arise within the fuel line, and particularly at the location of the uncoupler, and in some instances, has actually forced the coupling device to prematurely come apart. These devices also require separation of their components by force oriented axially.
Existing fuel nozzles have a tip inserted into the vehicle fuel tank connected to valving and a handle opposite the tip as is commonly known. A fuel line connects to the handle generally collinear with the tip. Occasionally, careless motorists presume the fueling has finished or hear the nozzle click off and drive away from the pump with the nozzle still inserted in the filler neck of the vehicle fuel tank.
When the motorist drives the vehicle away, the nozzle moves with the vehicle and the fuel line extends and becomes taught between the nozzle and the pump. Once the fuel line becomes taught, a fortunate motorist may have the nozzle slip out of the filler neck and fall to the surface of the dispensing facility. More often, the taught fuel line causes the nozzle to bend, generally at the tip near the filler neck and the fuel line to strain its joint to the handle. A motorist that drives away abruptly or at high speed will rapidly damage the nozzle, the vehicle, and likely separate the fuel line from the nozzle. Most dispensing stations have a breakaway connector locating near where the fuel line connects to the pump. However, when a fuel line separates from the nozzle, existing breakaway connectors do not retain the fuel located in the line between the breakaway connector and the nozzle. In a drive away incident, the fuel remaining within the fuel line spills and becomes an environmental hazard. The dispensing facility then has a broken nozzle, separated hose, and a spill to clean up.
This predicament has generally been recognized by the Applicant as primarily occurring because flow lines lack the ability to rotate or to pivot into an orientation parallel to the direction of travel of a vehicle driving off from a pump. Further, flow lines lack a lightweight and compact breakaway connector capable of locating proximate the handle of a nozzle.
Additionally, prior art breakaway couplings may have unbalanced internal forces. In a drive off, greater fluid forces are exerted in one direction upon one part of the breakaway coupling than upon the other, and are inherent because of the construction of the breakaway coupling device. When spontaneous and unbalanced high pressures are encountered, the pressure exerted upon one component of the breakaway coupling device in one direction, substantially differs from the fluid pressure that may be exerted upon the other component of the breakaway coupling device, and therefore, this pressure disparity tends to force the coupler to prematurely separate, in an untimely and dangerous fashion. This can and has occurred particularly where the fluid pressure in the hose may undergo a phenomenon that is equivalent to “water hammer.”
However, the present invention includes a smooth exterior, lightweight compact connector that connects flow line near the handle of a nozzle. Further, the connector induces forces to balance the internal forces applied against the main O ring seal, check valves, and separating pin. The main O ring seal endures fluid forces applied from fuel flowing through the invention. The two piece construction and shear pin construction provides counter forces that balance the fluid forces. Generally, the fluid forces tend to urge the connector apart while the forces induced by the present invention are equal in magnitude but opposite in direction to the fluid forces on the main O ring seal. The present invention neutralizes the fluid forces, minimizes nuisance breaks, stops fuel flow from a separated flow line, and minimizes handle damage.
The lengths of hose, fittings, and nozzles require connection among themselves and to service station pumping facilities. Hoses, fittings, and nozzles have couplings, often near the pump, that breakaway when an errant motorist drives away with a hose in a vehicle, and thus prevent a spill or worse, a fiery catastrophe. Until a breakaway, a coupling joins two sections of a fueling line and permits passage of fuel therethrough. As fuel pumps through the flow line, pressure spikes significantly and substantially throughout the hose, momentarily, and even at the location of the coupling, as when the flow is suddenly stopped, as for example, when the fuel tank is full. Hence, leakage at such couplers has frequently occurred in the field, and on occasion, untimely separation of the coupling has happened.
Couplings generally have two halves, a male fitting and a female fitting. The male fitting joins to a hose, fitting or nozzle and has an extended spacer means. The female fitting joins to a second hose, fitting, or nozzle and has a hollow cylindrical center to receive a spacer means. The female fitting engages the coupling by two diametrically opposed shear pins provided towards the rear of the female fitting and a plurality of locking bearings towards the front of the female fitting. Upon inserting the spacer means into the female fitting, the male fitting stands off from the female fitting until an errant motorist pulls the male fitting from the female fitting, the spacer or pin falls out, and the check valves close off the two pieces of hose formerly connected to the coupling.
Within the fittings of the coupling and the shear pins, pressure rises and falls depending upon the fuel flow through the coupling. Prior art designs provided an empty space between the locking bearings and the shear pins to absorb pressure fluctuations. In use though, the “water hammer” like effects during fueling induced excessive pressure upon the shear pins which would break repeatedly even with proper fueling and nozzle handling by motorists. Such nuisance breaks occur often and service stations then have to close a pump temporarily while the existing coupling is replaced.